1. Technical Field
The present invention relates to a cleaner used in image forming apparatuses such as printers, facsimiles and copiers, and to an image forming apparatus using the cleaner.
2. Description of the Related Art
Conventionally, in electrophotographic image forming apparatuses, residual a toner remaining on the surface of a photoreceptor even after a toner image thereon is transferred onto a recording material or an intermediate transfer medium is removed therefrom using a cleaner.
A cleaner installed in an image forming apparatus disclosed in Japanese published unexamined application No. JP-2000-66555-A includes a rectangle elastic blade, and a base end of the elastic blade is supported by a supporting member and an edge of the other end is contacted to the surface of an image bearer to block and scrape off a residual toner on the image bearer. Thereby, the residual toner is removed from the surface of the image bearer.
In attempting to meet a recent need of forming high quality images, a spherical toner prepared by a method such as polymerization methods (hereinafter referred to as polymerization toner) having a small particle is used. Since such polymerization toner has such an advantage as to have higher transfer efficiency than pulverization toner, the polymerization toner can meet the need.
However, the polymerization toner has such a drawback as not to be easily removed from an image bearer by a cleaning blade. This is because the polymerization toner has a spherical form and a small particle diameter, and easily passes through a small gap between the edge of a cleaning blade and the surface of the image bearer.
In attempting to prevent the polymerization toner from passing through a gap between the cleaning blade and the image bearer, it is necessary to increase the pressure to the cleaning blade contacted with the surface of the image bearer to enhance the cleanability of the cleaning blade.
However, when the contact pressure of the cleaning blade is increased, the friction between the cleaning blade and the image bearer is increased, and the tip of the cleaning blade is pulled by the image bearer in a moving direction thereof. Specifically, as illustrated in FIG. 7A, a cleaning blade 262 is pulled by the surface of an image bearer 23 in a moving direction of the image bearer due to increase of friction between the blade and the image bearer, thereby causing a problem (hereinafter referred to as everted-tip problem) in that an edge line 262c of the blade 262 is everted. In this regard, the thus everted tip has a restoring force, and therefore the tip tends to vibrate, resulting in generation of fluttering sounds.
In addition, when the cleaning operation is continued while the edge line 262c of the cleaning blade 262 is everted, a portion of the tip 262a of the cleaning blade 262, which is apart from the edge line 262c by few micrometers, is abraded as illustrated in FIG. 7B. When the cleaning blade 262 is further used for the cleaning operation, the portion of the tip 262a of the blade 262 is further abraded, resulting in lack of the edge line 262c of the blade 262 as illustrated in FIG. 7C. The cleaning blade 262 having no edge line cannot remove residual toner from the surface of the image bearer 23, thereby forming an abnormal image in which background thereof is soiled with residual toner.
A coating in which a fluorine compound monomer including a vinyl or an acryloyl group is mixed in an acrylic coating has attracted attention as a hard coat coating recently. When an acrylic coating in which a fluorine compound monomer is mixed is coated, the fluorine compound monomer is not uniformly present in an acrylic liquid and tends to be present in an air-liquid interface. After the acrylic coating is coated on an object, an UV light is irradiated to the coating such that the fluorine compound monomer is chemically bonded with an acrylic monomer of the acrylic coating at the outermost surface to noticeably decrease a frictional resistance of the surface of the object.
Because of these reasons, a need exists for a cleaner having high-durability and good cleanability.